I’ve been ‘out of it’ lately with huge workloads and so haven’t managed to get with all the analysis, but have still followed the posts with interest. The other day, I started to wonder whether, in the critical 4/5 …c6 variation, it might be good to look again at 4 …Bg7 5 Qd2! c6 6 Bh6 Bh6 7 Qh6 e5. Traditionally thought questionable I know, but White’s Queen is offside so maybe there could be resources? For example, after 8 de de 9 Nf3 Qe7 10 Bc4 b5 11 Bb3, how about 11 …Nbd7!?, not fearing to jettison the h-pawn after 12 Ng5 Rf8 13 Nh7 Nh7 14 Qh7 Nc5? Then after, say, 15 Qh6 a5 16 a3 Be6 17 Be6 Ne6 18 Qe3 0-0-0 19 0-0 Nd4, Black’s pressure looks to be worth exactly one pawn! I notice that the ChessLive database gives one game which went 11 …a5 with the same idea and maybe this is interesting too, though I think 11 …Nbd7 might be more precise.

About the PGN analysis. I'll just note that 11...Nxf6 in the PGN mainline, instead of 11...exf6 looks key if you want to avoid suffering as black. An earlier comment of mine about black possibly being denied equality after 9.Ne2 was based on me thinking 11...exf6 was more or less the way to go for black. The alternative 11...Nxf6 looks fully reasonable if you look at it for a while though, despite the structural degradation.

Also. It should be said that quite a high level of precision is needed here. Mostly for black, as always; even though there are ample chances for him to also pose problems for white and equalise very early against non-knowledgeable play and setups.

1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Bg5 a6 5.e5and now:5...dxe5 6.dxe5 Now a6 will be almost irrelevant and the threat on the knight is annoying.5...h6 6.Bf4 Nh5 (6...Nfd7 7.e6!? black gets an uninspiring position) 7.Be3 Basically black has no effective way of undermining the e5 point so white simply has a pleasant position.5...Nfd7 6.Qe2 (Shaw's recommendation) Black can not in the near term effectively hit white's center and needs to find some way of developing without being hit himself (no easy task).

1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Bg5 a6 5.e5and now:5...dxe5 6.dxe5 Now a6 will be almost irrelevant and the threat on the knight is annoying.5...h6 6.Bf4 Nh5 (6...Nfd7 7.e6!? black gets an uninspiring position) 7.Be3 Basically black has no effective way of undermining the e5 point so white simply has a pleasant position.5...Nfd7 6.Qe2 (Shaw's recommendation) Black can not in the near term effectively hit white's center and needs to find some way of developing without being hit himself (no easy task).

6. f4 d5!? in an interersting novelty to blow a hole in the White pawn centre

This 6...d5 move is the move to make work in order to put 5...Nbd7 on the table as a viable option for a repertoire.

When checking 6...d5 exploratively a few days ago I was very optimistic about black's chances and the positions he tended to get; which where of the unbalanced but still sound looking type. Now I don't know know really. White has a line where he has to show enormous accuracy, though in this line black seems to be denied equality and instead ends up searching for safe positions (which I have yet been able to force in analysis).

Once you play ..c6, you are committed to a particular structure and ideas. There are alternatives to 4. .. c6, some of which can transpose.

Conceptually I see 4...c6 as preparation for b5 or d5, though almost everyone goes for b5 based setups and after having gone b5 going d5 becomes harder. A definite point behind c6 is also that black can send his queen to a5 early.

Some also cover 4.Bg5 c6 5.Qd2 Bg7 6.Bh6 (through various move orders).And of course there is GM Shaw - Playing 1.e4 (2016) who does cover 4.Bg5 c6 5.Qd2 b5 6.e5 substantially and well (though he does not cover alternate black fifth moves, 5...Bg7 excluded).

Where does that leave us then? Basically there seems to be a significant leaning towards 4.Bg5 c6 5.Qd2 b5, only 6.e5 has not been taken seriously thus far. Of the above books Vigus does best (anyone surprised? ) actually covering 6.e5; although Shaw's suggestion probably just improves over the line Vigus gives.

So we have:1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Bg5 c6 5.Qd2 b5 (The line in Pirc litterature and one which Shaw recently tried to show deficiencies in after 6.e5)1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Bg5 c6 5.Qd2 Bg7 (Given in various Pirc litterature as an alternative to the 5...b5 line)1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Bg5 c6 5.Qd2 Nbd7 (Mentioned once in Pirc litterature)And that is it.

Knowing not many lines are actually covered in Pirc litterature a natural question is to ask if there are alternatives to the above lines, which have not received coverage thus far. From what I can see the following moves have been played (popularity order):

Of course chess is about thinking and it would disappointing to miss some nice move for lack of this. So is it possible to think of more moves? Somewhat not entirely out of place looks to me the following:

Listed above are certainly a handful of black fifth moves, though is any of them attractive enough to form a repertoire around? I don't know but I can say that of all the moves listed (including 5...b5 and 5...Bg7 played hundreds of times) there is only one which I think is good Edit: has potential enough to be used as repertoire staple.